1. Field
The present disclosure pertains to the field of computing and computer systems, and, more specifically, to the field of power control of microprocessors.
2. Background
Some computing systems and microprocessors may contain multiple processing elements, or “cores”, to execute instructions of a program and perform some function in response thereto. For example, multiple processing cores may exist on the same processor die. Alternatively or conjunctively, some computer systems may include multiple processors, each having one or more processing cores. Moreover, some computing systems and microprocessors may be able to control power consumption of one or more processing cores by placing the cores in various power states, which may be defined according to a power specification, such as ACPI (defined) or some other specification.
However, processing systems and microprocessors may not be able to control the power states of each processing core independently, but must coordinate a power state changes among the various cores present in the system or processor by using such techniques as polling the power state of other processing cores or otherwise detecting the power state of other cores in some way. Accordingly, the power states of a processing core may be dependent upon at least one other processing core in a computing system or processor.
Because some processing systems or processors may rely on the processing states of one or more cores to control the processing state of a particular core, the system or processor may require additional control circuitry to change a core's power state. Furthermore, polling or otherwise detecting power states of other processing cores before being able to change the power state of a particular processing core may require additional time before the core's processor state may be changed, which can degrade processing performance. Ironically, the additional circuitry needed to coordinate a power state change of a processing core with one or more other processing cores may cause the processor or system to draw more power, thereby at least partially offsetting the power consumption reduction of reducing a power state change intended to conserve power.